RFR: 8335347: GenShen: Revert change that has adaptive heuristic ignore abbreviated cycles

[William Kemper]

Additional performance testing has shown no benefit from this feature. In fact, latency is degraded on the extremem benchmark with this feature enabled.

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Commit messages:
 - Merge remote-tracking branch 'shenandoah/master' into revert-ignore-short-cycles
 - Do not ignore abbreviated cycles

Changes: https://git.openjdk.org/shenandoah/pull/455/files
  Webrev: https://webrevs.openjdk.org/?repo=shenandoah&pr=455&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8335347
  Stats: 26 lines in 10 files changed: 1 ins; 14 del; 11 mod
  Patch: https://git.openjdk.org/shenandoah/pull/455.diff
  Fetch: git fetch https://git.openjdk.org/shenandoah.git pull/455/head:pull/455

PR: https://git.openjdk.org/shenandoah/pull/455